Disazo dye and process of making same.



UNITED STATES Pram OFFICE.

THILO KROEBER, OF BASEL, SWITZERLAND, A SSIGNOR TO B IRMOF SOCIETY OF CHEMICAL INDUSTRY IN BASLEJ OF BAS-EL, SWITZER LAN D.

DIS AZO DYE AND PROCESS OF MAKING SAME.

To all whom it may concern:v

Be it known that I, TnrLo KROEBER, chemist and doctor ofphilosophy, a subjectof the Duke of Saxeu iltenburg, and a resident of Basel, Switzerland, have invented tholic coi'npounds may be employed the 1:4

naph'thohsuliomc acid, I or 2:6 naphtholsulfonic. acid,a,sul'lo derivative of 1:8 dioxynaphthalene, &c., andas non-sulfonated naphtholic compound 'beta-naphthol 2:7 .or

' 1:5 dioxynaphthalene are preferably employed.

'The new dyestuil's correspond to the formula I l=N--G,,H( y.)- (OH)z They dye wool in an acid-bath from brown to yiolet tints, which turn to black on treat ment with chromium compounds. They dissolve in water with a coloration varying 'li'om violet and blue to black and in concentrated sulfuric acid with a .blue to black 001 oration.

Example: 12.5 parts, by weight, of dram1- I Specification of Letters Patent Application filed anuary 3, 1906; Serial No. 294,473.

Patented June 19, 1906.

ation. The diazotization being complete, the mass is poured into a cold watery solution containing twenty-five parts, by weight,

of the sodiumsalt of 1:4 naphthol-sulfonic acid and fifty parts, by weight, of crystallized sodium acetate. Immediately an intermediate product is formed and precipitated as a gelatinous red paste. As soon as the tetrazophenol has entered into reaction the whole is combined at ordinary temperature with fifteen parts, by weight, of beta-n aphthol dissolved in one hundred. parts,

by weight, of Water, with the addition of forty parts, by weight, of soda-lye of 30 Bau-m. I The combination is now stirred" for about five to six hours, then further stirred-during about two hours at about centigrade, then heated at about 80 centi grade, and the dyestufi' is salted out in the usual manner. If necessary, it may be purified by dissolving the same in hot water and salting out with common salt. It forms in a dry and pulverized state a dark powder with bronze-like luster, soluble in hot water with a bluish-violet, color and in concentrated sulfuric acid (66 Baurn) with a darkblue color, violet-black flakes being precipitated on the addition of sufficient ice-water The dyestufi' proto the aforesaid solution. duces on wool in an acid-bath brownishviol'et shades, which turn to a deep violetblack on the treatment with potassium bichromate and exhibit then very great fast ness to milling, washing,'p0tti1ig, and light. I In the aforesaid example the employment of sodium acetate may be omitted, and it can be proceeded in such a manner-that the said tetrazophenol solution 'is combined directly with the naphth0lsulfonic acid solution in the presence of soda-lye (forty parts,

by weight) and then immediately with the solution of fifteen arts, "by weight, of betanaphthol'dissolve in the necessary quantity of soda-lye.

In an analogous manner valuable dyestuils with quite similar properties are ob-' tained if in the above example the'sodiurn salt of the 1-;4 naphthol-sulfonic acid is re-- placed by the equivalent quantity of 1:5 naphthol-sulfonic acid or 2:6 naphthol-sulfonic acid' or a sulfonic acid 10f ,1:8 dioxy naphthalene and if the beta-naphthol is replaced by the corresponding quantity. of a dioxynaphthalcneas,for example, 2:7 or

1:5 dioxynaphthalene.

What 1 c1aimis- 1. The process for the manufacture of disazo'dyestuffs, which consists in combining one molecule of the tetra zo derivative of the diamidophenol (OH :NH :NH '=1:2 :4) with one molecule of an azo c0l0ri1*.,':matter compound to form an intermediate product and then combining the intermediate product thus obtained with a further molecule of an azo coloring-matter compound, as described.

2. The process for the manufacture of disazo, dyestuffs which consists in combining one molecule 'of the tetrazo derivative of the diamidophenol (OH :NH :N H 1:2 :4) first with one molecule of a sulfonated naphtholic compound to form an intermediate product and then combinin the intermediate product thus obtained wit 1 onemolecule of a non-sulfonated naphtholic compound as described. 1

3. As new products, the disazo dyestuffs corresponding to the formula:

which dye wool in an acid-bath brown to violet tints, which turn to black by treatment with chromium compounds and constitute in dry state dark powders soluble in water with a coloration varying from violet and blue to black and in concentrated sulfuric acid with 'a blue to black coloration;

4. As a new article of manufacture, the herein-described disazo dyestuffs derived from the tetrazo derivative of the di'amidophenol (OH :NH :NH,=1:2 :4), 1:4 naph thol-sulfonic acid and beta-naphtho], which dyes wool in an acid-bath brownish-violet tint turning on thetreatment with chromium compounds to a deep violet -b ack very fast to milling, washing, potting and light, and constitutesin dry state a dark powder with bronze-like luster, soluble in water with a bluish-violet color and in concentrated sulfuric acid with a dark-blue color. 4

In testimony whereof I have hereunto signed my name, this 21st day of December,

- 1905, in the presence of two subscribing wit nesses.

TlllLU. KROEBER'.

Witnesses: I

GEO. GIFFORD, AMAND BITTER; 

